The invention relates to an insulated collector assembly and a tube equipped with such a collector. To increase the efficiency of electronic tubes and in particular progressive-wave tubes, the electrons are collected at the end of travel by an electrode, the collector being brought up to a potential between that of the cathode and ground (potential of the anode).
For high-power tubes this electrode dissipates several kilowatts. Its cooling poses delicate problems. In fact, whatever the system of cooling, it is desirable for the cooling fluid only to come into contact with materials at ground potential, especially when the tube is cooled by conduction.
When the power dissipated reaches several kilowatts, it is desirable for the collector to be solid and to have the shape of a cone hollowed out in a metal cylinder so as to distribute heat under the best conditions in the collector. In this case, it is difficult to braze the copper mass to the inside of an insulating cylinder, because of the thermal expansion coefficient differences between the metal and the insulator, which is generally copper and a ceramic.
The invention provides an insulated collector for a power tube which resolves this problem.